While a variety of biocidal polymers [e.g., quaternary ammonium salts, phosphonium materials, halogenated sulfonamides, and biguanides (see Trends Polym. Sci. 4:364 (1996))] have been synthesized and tested for biocidal activity, a relatively new class of compounds known as N-halamines has been shown to have far superior properties including biocidal efficacy, long-term stability, and rechargeability once the efficacy has been lost. One example of a biocidal N-halamine polymer is poly-1,3-dichloro-5-methyl-5-(4′-vinylphenyl)hydantoin, which is an inexpensive derivative of polystyrene, and which was first described in U.S. Pat. No. 5,490,983, incorporated herein by reference in its entirety. Subsequent disclosures of its biocidal properties for use in disinfecting applications for water filters have recently occurred [see Ind. Eng. Chem. Res. 33:168 (1994); Water Res. Bull. 32:793 (1996); Ind. Eng. Chem. Res. 34:4106 (1995); J. Virolog. Meth. 66:263 (1997); Trends in Polym. Sci. 4:364 (1996); Water Cond. & Pur. 39:96 (1997)]. The polymer is effective against a broad spectrum of pathogens including Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli Candida albicans, Klebsiella terrigena, Legionella pneumophila, and rotavirus, among others. The polymer causes large log reductions in contact times on the order of a few seconds in water disinfectant applications. Furthermore, the polymer is effective at pH values at least in the range of about 4.5 to about 9.0 and at temperatures at least in the range of about 4° C. to about 37° C., and is capable of action even in water containing heavy chlorine demand caused by bioburden.
The biocidal hydantoin polymer is insoluble in water and organic compounds and will thus not migrate in liquid media. The polymer is stable for long periods of time in dry storage (a shelf life of at least one year at ambient temperature). The polymer can be produced on an industrial scale. Furthermore, all evidence obtained to date suggests that the polymer is non-toxic and non-sensitizing to humans and animals upon contact.
A variety of microorganisms such as certain bacteria, fungi, and yeasts are capable of aiding the decomposition of bodily fluids, such as urine and blood, or in the formation of biofilms, that produce undesirable odors in otherwise useful commercial products. Bacteria such as Bacterium ammoniagenes and Proteus mirabilis are known to accentuate the decomposition of urea to form noxious ammonia gas through a urease enzyme catalysis mechanism (see for example U.S. Pat. No. 5,992,351). The polymer poly-1,3-dichloro-5-methyl-5-(4′-vinylphenyl)hydantoin has been shown to be effective at inactivating Proteus mirabilis and thus minimizing the undesirable odor created by ammonia gas (U.S. patent application Ser. No. 09/685,963, incorporated herein by reference in its entirety). Also, the polymer is insoluble in bodily fluids so as not to migrate to skin surfaces, thus rendering it useful for disposable diapers, incontinence pads, bandages, sanitary napkins, and pantiliners.
However, the preparation of poly-1,3-dichloro-5-methyl-5-(4′-vinylphenyl)hydantoin as uniform particles is tedious, requiring a three-step synthesis and the use of reagents such as potassium cyanide and carbon disulfide, as well as a high-pressure reactor in one of the steps. When fully chlorinated, the polymer binds about 20% by weight chlorine, which causes a noticeable chlorine odor. Thus, new biocidal compounds are desired to be developed having fewer of these disadvantages.
U.S. patent application Ser. No. 09/948,945, incorporated herein by reference in its entirety, describes biocidal beads of highly crosslinked polystyrene having pendant N-halamine groups. In this application, the aforementioned shortcomings in the prior art were addressed. However, other alternatives are desired. The present application fulfills the shortcomings of the prior art and provides further related advantages.